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Recent advances in segmented low‐gain avalanche detectors (LGADs) make them promising for the position‐sensitive detection of low‐energy X‐ray photons thanks to their internal gain. LGAD microstrip sensors fabricated by Fondazione Bruno Kessler have been investigated using X‐rays with both charge‐integrating and single‐photon‐counting readout chips developed at the Paul Scherrer Institut. In this work it is shown that the charge multiplication occurring in the sensor allows the detection of X‐rays with improved signal‐to‐noise ratio in comparison with standard silicon sensors. The application in the tender X‐ray energy range is demonstrated by the detection of the sulfur Kα and Kβ lines (2.3 and 2.46 keV) in an energy‐dispersive fluorescence spectrometer at the Swiss Light Source. Although further improvements in the segmentation and in the quantum efficiency at low energy are still necessary, this work paves the way for the development of single‐photon‐counting detectors in the soft X‐ray energy range. [ABSTRACT FROM AUTHOR]

The Source Follower (SF) as the first amplification stage of the front-end electronics has proven to be an effective tool for low-noise read-out of silicon radiation sensors. Since the noise properties of a well-designed amplification circuit are mainly determined by its very first stage, constraints on the subsequent electronics are relaxed. Moreover, since the SF is characterized by a low output resistance, once it is completely integrated into the detector substrate, the connections to the out-of-chip part of the circuit are also relaxed. The effectiveness of this solution and the overall performance of the system depend on the sensor properties. In this paper, by presenting analytical calculations and measurements, we identify the sensor types that could profit from the advantages provided by the integrated SF, and the devices where the SF shows some pitfalls. Although the results presented in this paper have been obtained with an integrated JFET technology, the conclusions are valid for whatever technology the SF is made. [ABSTRACT FROM AUTHOR]

We introduce a double-sided variant of low gain avalanche detector, suitable for pixel arrays without dead-area in between the different read-out elements. TCAD simulations were used to validate the device concept and predict its performance. Different design options and selected simulation results are presented, along with the proposed fabrication process. [ABSTRACT FROM AUTHOR]

This paper deals with a radiation hardness study performed on double-sided 3D strip sensors with passing-through columns. Selected results from the characterization of the irradiated sensors with a beta source and a laser setup are reported and compared to pre-irradiation results and to TCAD simulations. The sensor performance in terms of signal efficiency is found to be in good agreement with that of other 3D sensors irradiated at the same fluences and tested under similar experimental conditions. [ABSTRACT FROM AUTHOR]

The planned luminosity upgrade of the CERN LHC to the super LHC (sLHC) requires investigation of new radiation hard tracking detectors. Compared to the LHC, tracking detectors must withstand a 5–10 times higher radiation fluence. Promising radiation hard options are planar silicon detectors with n-side readout and silicon detectors in 3D technology, where columnar electrodes are etched into the silicon substrate. This article presents beam test measurements performed with planar and 3D n-in-p silicon strip detectors. The detectors were irradiated to different fluences, where the maximum fluence was 3\times 10^15 1 MeV neutron equivalent particles per square centimeter (neq/\rm cm^2) for the planar detectors and 2\times 10^15~neq/\rm cm^2 for the 3D detectors. In addition to signal measurements, charge sharing and resolution of both detector technologies are compared. An increased signal from the irradiated 3D detectors at high bias voltages compared to the signal from the unirradiated detector indicates that charge multiplication effects occur in the 3D detectors. At a bias voltage of 260 V, the 3D detector irradiated to 2\times 10^15~neq/\rm cm^2 yields a signal almost twice as high as the signal of the unirradiated detector. Only 30% of the signal of an unirradiated detector could be measured with the planar detector irradiated to 3\times 10^15~neq/\rm cm^2 at a bias voltage of 600 V, which was the highest bias voltage applied to this sensor. [ABSTRACT FROM AUTHOR]

Abstract: The projected luminosity upgrade of the large hadron collider (LHC), the sLHC, will constitute a challenging radiation environment for tracking detectors. Massive improvements in radiation hardness are required with respect to the LHC. In the layout for the new ATLAS tracker, silicon strip detectors (SSDs) with short strips cover the region from 28 to 60cm distance to the beam. These SSDs will be exposed to fluences up to , hence radiation resistance is the major concern. It is advantageous to fuse the superior radiation hardness of the 3D design originally conceived for pixel-style applications with the benefits of the well-known planar technology for strip detectors. This is achieved by ganging rows of 3D columns together to form strips. Several prototype sLHC detector modules using 3D SSD with short strips, processed on p-type silicon, and LHC-speed front-end electronics from the present ATLAS semi-conductor tracker (SCT) were built. The modules were tested before and after irradiation to fluences of . The tests were performed with three systems: a highly focused IR-laser with spot size to make position-resolved scans of the charge collection efficiency (CCE), a -source set-up to measure the signal levels for a minimum ionizing particles (MIPs), and a beam test with 180GeV pions at CERN. This article gives a brief overview of the performance of these 3D modules, and draws conclusions about options for using 3D strip sensors as tracking detectors at the sLHC. [Copyright &y& Elsevier]

Due to their low depletion voltage, even after high particle fluences, improved tracking precision and momentum resolution, and reduced material budget, thin substrates are one of the possible choices to provide radiation hard detectors for future high energy physics experiments. In the framework of the CERN RD50 Collaboration, we have developed PIN diode detectors on membranes obtained by locally thinning the silicon substrate by means of TMAH etching from the wafer backside. Diodes of different shapes and sizes have been fabricated on 50-μm and 100-μm thick membranes and tested, showing a low leakage current (of 300 nA/cm³) and a very low depletion voltage (in the order of 1 V for the 50 μpm membrane) before irradiation. Radiation damage tests have been performed with 58 MeV lithium (Li) ions up to the fluence of 1014 Li/cm² in order to determine the depletion voltage and leakage current density increase after irradiation. Charge collection efficiency tests carried out with a β- particle source have been performed on both nonirradiated devices and samples irradiated upto 1.8 × 1013 Li/cm². Results reported here confirm the advantages of thinned diodes with respect to standard 300-μm thick devices in terms of low depletion voltage and high charge collection efficiency. [ABSTRACT FROM AUTHOR]

The paper presents the simulation studies of 10 μ m pitch microstrips on a fully depleted monolithic active CMOS technology and describes their potential to provide a new and cost-effective solution for particle tracking and timing applications. The Fully Depleted Monolithic Active Microstrip Sensors (FD-MAMS) described in this work, which are developed within the framework of the ARCADIA project, are compliant with commercial CMOS fabrication processes. A set of Technology Computer-Aided Design (TCAD) parametric simulations was performed in the perspective of an upcoming engineering production run with the aim of designing FD-MAMS, studying their electrical characteristics, and optimizing the sensor layout for enhanced performance in terms of low capacitance, fast charge collection, and low-power operation. A fine pitch of 10 μ m was chosen to provide high spatial resolution. This small pitch still allows readout electronics to be monolithically integrated in the inter-strip regions, enabling the segmentation of long strips and the implementation of distributed readout architectures. The effects of surface radiation damage expected for total ionizing doses of the order of 10 to 10 5 krad were also modeled in the simulations. The results of the simulations exhibit promising performance in terms of timing and low power consumption and motivate R&D efforts to further develop FD-MAMS; the results will be experimentally verified through measurements on the test structures that will be available from mid-2021. [ABSTRACT FROM AUTHOR]

Abstract: Silicon strip detectors are widely used as part of the inner tracking layers in particle physics experiments. For applications at the luminosity upgrade of the Large Hadron Collider (LHC), the sLHC, silicon detectors with extreme radiation hardness are required. The 3D detector design, where electrodes are processed from underneath the strips into the silicon bulk material, provides a way to enhance the radiation tolerance of standard planar silicon strip detectors. Detectors with several innovative 3D designs that constitute a simpler and more cost-effective processing than the 3D design initially proposed were connected to read-out electronics from LHC experiments and subsequently tested. Results on the amount of charge collected, the noise and the uniformity of charge collection are given. [ABSTRACT FROM AUTHOR]

Abstract: Vertex detectors for the next LHC experiments upgrades will need to have low mass while at the same time be radiation hard and with sufficient granularity to fulfil the physics challenges of the next decade. Based on the gained experience with 3D silicon sensors for the ATLAS IBL project and the on-going developments on light materials, interconnectivity and cooling, this paper will discuss possible solutions to these requirements. [Copyright &y& Elsevier]

Abstract: We present a new 3D detector architecture aimed at simplifying the manufacturing process making it more suitable for high volume production. In particular, the proposed device features electrodes of one doping type only, e.g., columns in a p-type substrate. We report on TCAD simulation results providing deep insight into the static and dynamic behavior of this detector, highlighting its advantages and potential drawbacks. The fabrication process we intend to use is also described along with results from the morphological characterization of the most critical technological steps. [Copyright &y& Elsevier]

Position-resolved timing characterisation tests were performed on individual pixels of hexagonal and trench 3D silicon sensors. An IR laser was used to deposit energy equivalent to 1 MIP with a 1 μ m spatial resolution onto each sensor, which were attached to custom-designed fast read-out electronics chips. Time of Arrival (ToA) values obtained were (544 ± 29.8) ps for the hexagonal geometry, and (515 ± 8.2) ps for the trench geometry. • IR laser scan performed on single pixels of hexagonal and trench 3D silicon sensors. • 1 MIP of energy was deposited, using a 1-micron space resolution in the scan. • Timing resolution of hexagonal pixel was 29.8 ps. • Timing resolution of trench pixel was 8.2 ps. [ABSTRACT FROM AUTHOR]

Abstract: The CMS silicon pixel detector is the tracking device closest to the LHC p–p collisions, which precisely reconstructs the charged particle trajectories. The planar technology used in the current innermost layer of the pixel detector will reach the design limit for radiation hardness at the end of Phase I upgrade and will need to be replaced before the Phase II upgrade in 2020. Due to its unprecedented performance in harsh radiation environments, 3D silicon technology is under consideration as a possible replacement of planar technology for the High Luminosity-LHC or HL-LHC. 3D silicon detectors are fabricated by the Deep Reactive-Ion-Etching (DRIE) technique which allows p- and n-type electrodes to be processed through the silicon substrate as opposed to being implanted through the silicon surface. The 3D CMS pixel devices presented in this paper were processed at FBK. They were bump bonded to the current CMS pixel readout chip, tested in the laboratory, and testbeams carried out at FNAL with the proton beam of 120GeV/c. In this paper we present the laboratory and beam test results for the irradiated 3D CMS pixel devices. [Copyright &y& Elsevier]

Abstract: While the Large Hadron Collider (LHC) at CERN has started operation in autumn 2008, plans for a luminosity upgrade to the Super-LHC (sLHC) have already been developed for several years. This projected luminosity increase by an order of magnitude gives rise to a challenging radiation environment for tracking detectors at the LHC experiments. Significant improvements in radiation hardness are required with respect to the LHC. Using a strawman layout for the new tracker of the ATLAS experiment as an example, silicon strip detectors (SSDs) with short strips of 2–3cm length are foreseen to cover the region from 28 to 60cm distance to the beam. These SSD will be exposed to radiation levels up to , which makes radiation resistance a major concern for the upgraded ATLAS tracker. Several approaches to increasing the radiation hardness of silicon detectors exist. In this article, it is proposed to combine the radiation hard 3D-design originally conceived for pixel-style applications with the benefits of the established planar technology for strip detectors by using SSDs that have regularly spaced doped columns extending into the silicon bulk under the detector strips. The first 3D SSDs to become available for testing were made in the Single Type Column (STC) design, a technological simplification of the original 3D design. With such 3D SSDs, a small number of prototype sLHC detector modules with LHC-speed front-end electronics as used in the semiconductor tracking systems of present LHC experiments were built. Modules were tested before and after irradiation to fluences of . The tests were performed with three systems: a highly focused IR-laser with spot size to make position-resolved scans of the charge collection efficiency, an -source set-up to measure the signal levels for a minimum ionizing particle (MIP), and a beam test with 180GeV pions at CERN. This article gives a brief overview of the results obtained with 3D-STC-modules. [Copyright &y& Elsevier]

Abstract: Recently, we presented a new 3D detector architecture aimed at simplifying the manufacturing process, making it more suitable for high-volume production. In particular, the proposed device features electrodes of one doping type only, e.g., n+ columns in a p-type substrate. In this paper we report on the fabrication at ITC-irst of the first batch of prototypes. The main issues related to the fabrication process along with preliminary results from the electrical characterization of different detectors and test structures are discussed. [Copyright &y& Elsevier]

Abstract: The 3D silicon radiation detectors are very promising devices to be used in environments requiring extreme radiation hardness, such as the super-LHC experiment at CERN. A drawback of this detector is the very long and non-standard fabrication process, which makes the mass production of these devices very critical. A possible simplification of the manufacturing process relies on a new type of 3D architecture, called 3D-single-type-column detector, that we have introduced in previous works. In this paper we report on the fabrication process of the first batch of detectors and on selected results from the electrical characterization of 3D test structures, covering leakage current, capacitance and breakdown voltage measurements. [Copyright &y& Elsevier]